Pilot-valve.



E. V. ANDERSON.

PILOT VALVE.

APPLICATION FILED SEPT. 16, 1914.

1,209,795. Patented Dec. 26,1916.

WITNESSES INVENTOR {M W. W W%M purine sra'ras ra rnu r enema,

EDWARD V. ANDERSON, OF MONESSEN, PENNSYLVANIA, ASSIGNOR 0F ONE-HALF T0 CHARLES E. GOLDEN, OF GRAFTON, PENNSYLVANIA.

riLo'r-vALvE.

Patented Dec. as, rare.

Application filed September 16, 1914. Serial No. 862,009.

To all whom it may concern Be it known that I, EDWARD V. ANDER- SON, a citizen of the United States, residing at Monessen, in the State of Pennsylvania, have invented certain new and useful Improvements in Pilot-Valves, of which the following in a specification.

My invention relates particularly to means for automatically operating large valves, and its primary objects are to provide a simplified and accurate adjustable pilot valve, to provide an eficient testing device for use while the main valve is in service, to improvethe construction of triple acting valves, and generally to improve the construction and operation of valves.

I have illustrated my invention in the accompanying drawing, which shows a partial side elevation and partial vertical central section of a triple acting valve and of the pilot used therewith.

In the drawing I have shown the main valve casing 3, having a valve seat partition 4 separating the fluid inlet (A) and the outlet (B). The opening is closed by the valve 5 supported on a vertical moving stem 6, which also carries a double piston 7 reciprocating in a cylinder 8 fixed in the casing. The casing is covered by a hood 9 through which projects a screw stem 10 with a handwheel 11, for closing the main valve manually, as is usual. The valve stem 6 is hollow, the opening being closed at the top by ball check 12, and it admits fluid from the high pressure side into the upper chamber (C) and also by means of port 13 into the chamber (D). The cylinder 8 and the piston 7 are provided with offset portions forming the cushioning chamber (E). It will be seen that by this construction the main valve 5 is cushioned in both its movements, and more particularly when near the closed position, by means of the entrapped fluid in offset chamber (E).

I provide a port (14:) communicating with the dashpot chamber (D), and to this port there is connected, by valved pipe 15, the casing 16 of the pilot valve. The pilot valve 18 is provided with a hollow extension 19 in which I provide the proper quantity of shot or other weight 20, to maintain the proper pressure difference. Cylinder 19 is closed by a plug 21; it rides freely between sets of lugs 23. The parts are all inclosed by cap 17 on the casing 16. Outlet pipe 22 goes directly to the header or other receptacle for the fluid from the low pressure side (B) of the main valve. Connected with the outlet port lt from the dashpot chamber (D), I also provide a small pipe 24 having a valve 25, located at any convenient point for manipulation of the operator. Its purpose is to manually relieve the pressure in the chamber (D) and allow the main valve to close while in service, in order to test its operation. Furthermore, I may arrange the pilot valve casing with the outlet 22 to the header, provided with a check valve 29, and on the other side also the outlet 22 having a test .valve 31, thus arranging for testing both the pilot valve and the main valve, while in service.

It will be seen that the live fluid will raise the main valve 5, and pass out the outlet through chamber (B), raising the piston 7 of the dashpot, which has pressure equalized on it by passage of the live fluid through the hollow stem and check valve 12, whence it may pass through the port (13) into the chamber (D) under the dashpot piston 7. It will, when open, be also under equalized pressure through the hollow stem, so far as concerns the outlet pressure in the header. Referring to the pilot valve it will be clear that by adjusting the weight 20, I can maintain a fixed difference between the boiler pressure on the inlet side (A) and the header pressure. Whenever this predetermined difference of pressure is reduced, reducing pressure above valve 18, the weight 20 aided by the header pressure will not be suflicient to overcome the boiler pressure on the underside of valve 18 and the pilot valve will open, thereby suddenly relieving the pressure in the chamber (D) under the dashpot piston 7, whereupon the live pressure on top of this piston will close the main valve 5, cushioning on chamber At any time, even when the valve is in service, its operation may be tested. by the simple expedient of opening the test valve 25, relieving pressure in the chamber (D) as before described, and closing the main valve. This is of great advantage, since the closing of the main valve by screw stem 10 does not give information as to the smooth working of the valve, besides which it puts the main time. In the form shown in Fig. 2, the

opening of the test valve 31, of course, serves as a test both for the pilot valve and for its proper operation of the inain valve.

I consider the simplicity of' the pilot valve as one of its principal advantages, The weight will be carefully adjusted "at the factory, whereupon the entire device is closed by the cap 17 leaving nothing tobe handled or to get outof order; while the simple single connection to the header is a marked advantage over any pilot valve heretofore used.

' Having thus described-my invention and illustrated its use, what I claim is the following:

1. The combination with a main valve having a dashpot device for balancing the valve in open position, of a pilot valve connected with the under chamber of said dashpot and arranged to relieve the pressure thereof when the relative pressure on top of the pilot valve is decreased beyond a prede- Copies of this patent may be obtained for termined limit and a valved test pipe connected to communicate with the top of said pilot" valve whereby to manually operate both the pilot valve and the main valve for testing in service.

2. A pilot valve for operating a main valve by release of pressure, comprising a casing having a perforated partition" forming' thevalve seat; a valve seated thereon provided with means to adjust its weight, a connection from the top of the casing to the low pressure side of the main valve, and a supplementary test pipe connected with the top of the pilot valve casing and provided with a valve, substantially as described. In testimony whereof I have hereunto signed my name in the presence of the two subscribed witnesses.

EDWARD V. ANDERSON. Witnesses A. J. SMITH,

A. N. SHUSTER.

five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

